I don't see what his brother's performance has to do with anything. Maybe he doesn't dope, maybe he doesn't respond, or maybe not even doping can make him very good. The Schlecks and the Yates are actually quite unusual. Philippe Gilbert's brother not being good on a bike doesn't make Gilbert less suspicious. Prudencio Indurain, Juraj Sagan, Antonio Nibali and many others all say hi.Mathieu is really that good and David van der Poel is really that normal. You would think if they both were doping, we would see something like the Schleck brothers, but nope.